Lamp for photographic dark rooms.



LAMP-POR PHOTOGRAPHIG DARK ROOMS.

No MODEL.

APPLICATION FILED JUNE 22. 1903.

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y MQW G-orney y PATLNTLD AUG. 23, 1904. H. L. sWART-z. LAMA PoR PHOTOGRAPHIG DARK Rooms.

. APPLIOATION FILED :um: 2z. 190s. No MODEL.

. Slaven-@40ry Maw@ -WaeSSe-Sf l @m f' No. 768,088. I PATENTED AUG. 23, 1904.

H. F.' SWARTZ.

LAMP PQR PHOTOGRAPHIG DARK ROOMS.

y APPLICATION FILED TUNE 22, 1903.

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4 .rs f@ /I V a H r g5 y www v UNrri-in STATES Patented August '23, 1904. Y

PATENT. OFFICE...

ILAiNIF FOR PHOTOGRAPHIC DARK ROOMS.

SPECIFICATION forming part of Letters Patent No. 768,088, dated August Application filed J'une 22, 1903. Serial No. 162,466. (No model.)

To will whom, t may concern:

Be it known that I, HERMAN F.A SWARTZ, of EastCleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Lamps or Lanterns for Photographic Dark Rooms, of which the following is a speciiication.

The invention relates to a lamp for a photographic dark room.

Colored fluids have been demonstrated to be much more transparent to non-actinic light than are any known solids and at the same time to be perfectly homogeneous, and hence reliable.

The object of the present invention isto apply this fact to use in a lamp for a photographic dark room and to construct a lamp for such use in which a fiuidcolor-filter is employed. I employ a cylindrical cell to contain the colored fluid, and inclosed within it is the source of light. Previous attempts to construct such a lamp have failed because the heat generated by the light employed has been too great for the iiuich particularly -when oil or gas is used. I seek to overcome this diiiiculty by the use of a ventilator, whereby there is automatically secured a continuous l cold blast against the top of the cell at the point where it would otherwise be the quickest to overheat. l

The invention will now be fully described, having reference to the accompanying drawings, and the novel features thereof will be particularly pointed out in the claims at the close of the specification.

In the drawings, Figure 1 is a vertical section online 1 1 of Fig. 2 of a lamp constructed according to my invention. Fig. 2 is a horizontal section on line 2 2 of Fig. 1. Fig. 3 is a plan. Fig. 4 is a modification showing the base fitted with an incandescent electric lamp. Fig. l5 shcws the base as adapted for the use o o1 1 represents the base on which is supported the annular cylindrical cell' 2. The cell 2 should be of some transparent material, the Word transparent being used in a broad sense of light-transmitting.

The lamp shown in the drawings is represented as being constructed for use with gas;

Argand-may be used, with or without a chimney. The cell 2 contains a colored iiuid 6, which acts as a filter for the light. Resting on the top of the annular walls of the cell 'is'a Ventilating-box 7, having an annular base 8 and a downwardly-extending annular flange 9, which iits inside of the inner wall of the cell and forms with the base 8 a screen to prevent the light from passing over the top of the filtering fluid. In the sides of the boX 7 are lateral openings 10 for ventilation. Blinds 11 extend from one edge of the openings 10 diagonally inward and past the other edge of the openings to prevent lateral escape of the light.y

A flue 13, preferably of metal, passes up through the covered top of the VentilatingboX 7. For lamps of large size the portion of the flue within the-ventilating-box may be made of double walls with asbestospacking;

rlhe luminant is located down within the body of the cell below the top, and the flue extends upward from the luminant, s o that the draft occasioned by the heat of the luminant and' by the flue causes the cold -air to be drawn down into the inner cylinder and up through the iiue. The blinds l1 are so curved as to give a spiral direction tothe incoming draft ofair, and this, together with the location of the luminant and flue, will cause the cool air to descend to the. bottom of the lamp by a spiral motion closely hugging' the inner wall of the inner cylinder, thus cooling the sides as well as the top of the cylinder.

The flue is preferably made extensible, so as to permit regulation of the draft by varying thelength of the flue, andto'this end a pipesection 14C is telescopically connected with the pipe 13 and secured by a set-screw 15. The flue is provided with an elbow 16 to prevent escape vof the light from above.

If oil is used in place of gas, a chimney 12 is employed, so as to deliver the draft at the IOO foot of the flame, as is required in all oilburners. This chimney is preferably made of mica and can be readily slipped over the ue when required to be used.

If an incandescent electric lamp is used, the base 19 is made to contain the connections and socket 17 for a lamp 18 of suitable poweru say four or eight candle power of the long thin varietyethe tip of the globe to come just below the mouth of the fiue. A base and lamp so fitted may be substituted for the one fitted for gas shown in Fig. 1. If oil is the luminant, the alternative base, Fig. 5, is used. The base 2O is also the reservoir. 21 is the socket for the burner 22. The burner Q2 differs from the well-known burner of ordinary use only in a wick-tube prolonged sufficiently to lift the ame to the center of the lamp. 23 is the ordinary device for regulating the wick, the rod being prolonged beyond the edge of the reservoir-base. With this burner an ordinary Welsbach chimney 24 may be used, resting upon the burner and encircling the flue. The burner need not be screwed into the socket, but may be pressed in as in most modern lanterns.

By the use of my invention the temperature of the liuid will not rise to a point higher than can be comfortably borne by the hand and a safe light can be emitted from forty to one hundred times as bright as would be given by any old-style lamp.

What I claim is# 1. In a lamp or lantern for a photographic dark room, a transparent double-walled, cylindrical cell containing a fluid color-filter between the walls, the inner cylindrical wall being open at the top, a luminant within the inner cylinder, a ventilator through which air is admitted into the luminant-chamber from above, and an outlet-Hue leading from the interior of the luminant-chamber, substantially as described.

2. In a lamp or lantern for a photographic dark room, a transparent, double-walled cylindrical cell containing a fluid color-filter between the walls, the inner wall being open both at the top and at the bottom, a luminant within the inner cylinder, aremovable base for the cell, vmeans for preventing the escape of light over the upper surface of the fluid filter, and means for automatically introducing a current of air into the luminant-chamber from above, and an outlet-fine from the luminantchamber, substantially as described.

3. In a photographic lamp or lantern for a dark room, a luminant, an annular transparent cell surrounding the luminant and containing a fiuid color-filter, a base which supports the cell and which prevents escape of light below the cell, a screen whichprevents escape of light over the top of the lilter, a ventilator through which air is admitted into thc luminant-chamber from above, and blinds which prevent escape of light through the ventilatoropenings, substantially as described.

4. In a lamp or lantern-for a photographic dark room, adouble-walled, cylindrical, transparent cell containing a liuid color-lilter between the walls, a luminant within the-inner cylinder, means for automatically introducing a current of air from without at the top of the cell and conducting it down against the inner wall of the inner cylinder, and an outletfine from the inner cylinder, substantially as described.

In a photographic lamp or lantern fora dark room, a luminant, an annular transparent cell surrounding the luminant and containing a fiuid color-lilter, a ventilating-box over the top of said cell having air-ducts through which outside air is admitted into the interior of the cell, an outlet-flue leading from the interior of the cell through the upper part of the ventilator, and means for preventing escape of light except through said filter, substantially as described.

6. In a photographic lamp or lantern for a dark room, a luminant, an annular transparent cell surrounding the luminant and containing a Huid color-filter, a ventilator over the top of said cell through which outside air is admitted into the interior of the cell, an extensible outlet-Hue leading from the interior of the cell through the ventilator, and means for varying the length of the outlet-liuc, suhstantially as described.

7. In a lamp or lantern for a photographic dark room, a double-walled, cylindrical, transparent cell containing a liuid color-filter between the walls and a luminant within the inner cylinder, a ventilator over the top of the cell through which outside air is admitted into the interior of the inner cylinder, an outletflue, and curved blinds which give direction to the draft so that the current is given a downward spiral motion into the cylinder against the walls and thence out through the llue, substantially as described.

In testimony whereof l. have aiiixed my signature in presence of two witnesses.

HERMAN F. SWAR'I'J.

litnessesz CLARENCE R. BIssnLL, EMMA JOHNSON.

lOO 

